Alternative Character Interpretation: In the beginning section at Destiny Islands, Riku and Sora's competitive relationship comes across differently depending on whether the player is superior, equal, or inferior to Riku.
Jafar is widely agreed to be one of the easiest Disney bosses in the game. The fight against his Genie form is especially anticlimactic, since despite being granted "phenomenal cosmic powers" by his transformation into an "all-powerful Genie", the only attack he'll use for most of the fight is slowly hurling easily-dodged balls of lava at Sora.
Rock Titan is another notable example. He's the final opponent of the very challenging Hades Cup, which you can only access late in the game. Like in the movie he's also gargantuan, probably one of the physically largest enemies in the game barring the final boss. However, while his attacks deal a lot of damage, he moves very slowly and his attacks are quite easy to avoid. As a result, he's generally considered to be one of the easiest bosses in the game, sometimes even the easiest.
After the slew of tough encounters in Hollow Bastion against Dragon-Maleficent and Ansem-Riku, the last boss of the level, Behemoth, is most definitely a pushover. It is incredibly slow, has very little means of actually attacking you beyond an easily-telegraphed-and-dodged homing energy sphere shot, keels over after being hit a few times so you can pummel it some more (this is actually a feint, as it attacks with powerful undodgeable lighting afterwards, but its range is very short and it gives you plenty of time to roll away before the attack comes out) and has a crippling weakness to Gravity magic.
Best Level Ever: There just hasn't been a world in this series yet that has been able to top this game's visit to Hollow Bastion in awesomeness. Aside from, perhaps, the sheer unnerving beauty (and frequent terror) of End of the World, the game's final world.
In Deep Jungle, one of the bosses is... a huge purple eggplant-looking fruit. The game simply feeds you the message "the fruit looks suspicious", then you're required to destroy it or Heartless will continue to spawn. The best explanation the game offers is Clayton uses it to trap Jane and Terk, but even then, the connection is obtuse/tenuous at best.
The battle with Chernabog is essentially this, since none of the characters comment on him, and he doesn't even get an entry in Jiminy's Journal, but as he's a highly popular character, no one is complaining too much.
Broken Base: The Atlantica level is pretty divisive - since it's the only world that requires a completely different gameplay system to accommodate the underwater setting (can't summon or use special attacks). The split increased since the world was changed for Kingdom Hearts II into an optional musical game - with some hating it even more, preferring the change or being indifferent to it.
Draco in Leather Pants: Riku while he's on the dark side. His fangirls just can't seem to admit he was ever in the wrong, and usually shift blame to Sora or Kairi for some absurd reason or other, often ignoring the far easier targets of Maleficent or Ansem.
Ending Fatigue: The final battle is a massive slooooooog, especially in this game where every individual boss battle ("boss" here can include any mandatory battle) gets this annoying twisty slowdown effect once you win. It consists of Ansem, a Darkside, Ansem again (this time without Donald or Goofy), Ansem on the World of Chaos, a horde of Shadows, the World of Chaos' main artillery tentacles, a horde of Darkballs, the World of Chaos' face, a horde of Invisibles and, finally, Ansem on the World of Chaos again in this very order.
Why Chernabog was included. This also applies to his reception in the series — he's regarded as one of the candidates for the series's example Best Boss Ever, at least thematically. When a Fantasia world was announced in Kingdom Hearts 3D: Dream Drop Distance, people had hoped he'd make an appearance. They were not disappointed.
Halloween Town also developed a strong fandom. In fact, according to BradyGames' strategy guide for Kingdom Hearts II, the reason why it was included in the subsequent games was because of its overwhelming fanbase. It even got some the merchandise based on that single world. Ironically, it was the only worldnote excluding the now-illegitimateDeep Jungle to not appear in the manga, and was even excluded from the novel.
Epileptic Trees: The Another Side, Another Story secret ending from the Final Mix version. Fans analyzed this video to death, getting crazy theories out of practically every single frame and setting internet forums on fire. The new Ansem Reports were a big source of Fan Wank as well. Although all theories were Jossed, fans never stopped to come up with theories about where the series would go in the next installment.
Evil Is Cool: Maleficent was already an example in her film, but ascends to new heights as the leader of the Disney Villains, and turning into her dragon form for a second boss fight.
First Installment Wins: The series goes on and quality is always debated, but the debut installment seems to be destined to be the one everyone will remember the most due to the sheer hype and reaction surrounding the concept and the one with the highest sales.
Fountain of Memes: Almost everything that comes out of Ansem's mouth is pure gold (or petroil, because "DARKNESS!"). They just haven't been able to recapture Billy Zane's magic ever since.
Choosing the Staff during Dive to the Heart. This sacrifices extra item slots earned by the Sword and Shield, but the Staff option gives Sora more MP to start with and a higher MP cap than the other two. Magical power is based purely on max MP, and the extra points also exponentially increase the number of spell uses. This means a high-level Sora can wipe out hordes of endgame enemies with almost zero-cost Blizzagas or cast Gravigas that deal 100% of the opponent's maximum health. Final Mix further favors the Staff with the new Ripple Drive finisher, which strikes a wide area with damage that is based on MP but doesn't expend it, meaning Staff-users who give up the Sword don't even feel the pain of low physical damage. Primarily physical-based users have another benefit: starting with the Staff gives the largest amount of starting Ability Points, while having high MP allows you to essentially spam the extremely powerful Sonic Blade, Strike Raid, and Ars Arcanum. Early Game Hell is a factor, but the Staff's advantages start to show as soon as Wonderland, and by the end of the first ring of worlds it has already left the Sword and Shied far behind.
Bambi is one of the greatest summons in Kingdom Hearts due to him spreading ridiculous numbers of MP orbs—your spells are basically free to use for the duration. Killing high numbers of enemies with Bambi out will both increase his dropped orbs and results in him dropping items and materials. Summon Bambi in a sufficiently infested area and you've got a self-sustaining item farm. He's also available once per room, meaning you can see him quite often.
Tinker Bell also merits discussion. Unlike the other Summons, Tink does not replace any allies on the battlefield and lacks a depleting MP bar, meaning that she will only leave if dismissed manually or upon Sora's death. Tinker Bell will constantly heal Sora and his allies while active and will revive Sora upon death before she leaves. Combined with Second Wind and other Support Abilities, there's little you'll need to worry about as long as you're sufficiently leveled, and Tink's Regen effect largely counteracts the need to spend MP on healing, meaning Sora is free to use Aeroga, Graviga, Strike Raid, Ars Arcanum, etc. instead. Of course, you can't perform any Summons in fights where Sora is down at least one partner and Neverland is the third-to-last world traveled to, but she comes in handy for tough late-game battles like Maleficent's dragon form and Chernabog. It's especially useful for the Bonus Boss Kurt Zisa—Tink is the perfect counter to Zisa's deadly attacks and its ability to lock Sora's own magic.
The Aero spell. It creates a shield around Sora that halves incoming damage and deals MP-scaled chip damage to enemies in contact with Sora. It will also stunlock many enemies. This can trivialize many big fights, including boss fights—even Sephiroth becomes notably easier. It's telling that (1) Kingdom Hearts has never featured another damaging barrier like this, and (2) one of the Bonus Bosses, the Ice Titan, specifically tries to counter Aeroga.
Stop works on a lot more things than it seems like it should, including a fairly large number of bosses. Stacking MP causes its duration to rise to where Sora can easily make back Stop's casting cost with the MP he recovers from pounding on the frozen enemies.
Your party members, Donald and Goofy, about halfway through the game. Early on, at times the only thing that prevents them from being a liability is the fact that they don't get permanently KO'd in battle. note They ARE "cartoon" (let alone Disney) characters, after all. Once they start getting good stats, weapons and abilities, they may just carry you. Goofy gets insane amounts of HP and defense, meaning he can take hits for a loooong time, while Donald's massive MP means he can clear swarms of Heartless with only one spell at times. It's telling that the hardest battles of the game are ones where you don't have party members, and even in Final Mix Proud Mode the easiest way to defeat the final boss is, once you rescue Donald and Goofy, to simply fly around and avoid attacks far away from him and spam the Triangle button (which commands Donald and Goofy to attack your target immediately), while locked on to him. His health will drain extremely fast, and the only thing preventing them from doing the job entirely without you contributing at all is the fact that Sora must inflict the final hit.
It is possible to get the EXP Ring, one of the four Experience Booster items, before battling Oogie Boogie and/or Ursula by completing 100 Acre Wood in the 1.5 version. Torn Pages are located in Agrabah, Monstro, Halloween Town, and Atlantica, while one can be obtained by saving 50 Dalmatians, which can be accomplished upon reaching Halloween Town. Combine that with a new accessory slot for Sora at Level 42 (if he picked the sword) and an extra MP bar from it, Level Grinding is less frustrating throughout Neverland and Hollow Bastion in the lead-up to Maleficent and Ansem.
Invisibles and Angel Stars, the two new enemy types in End of the World, are each this in their own right. Angel Stars can hit Sora from across the room, can fly out of reach, and can take a defensive stance that blocks all attacks, while Invisibles are very fast sword-wielders that can enter an invincible state where they surround Sora with a ring of fire requiring a carefully-timed Dodge Roll to avoid. Both have tons of HP and require advanced magic like Gravity and Stop to defeat painlessly.
Final Mix introduces a large number of Puzzle Boss Heartless that drop rare synthesis materials when slain correctly. Of these, the most dangerous is the Sniperwild, a purple version of Bouncywild that must be slain without being seen by it to drop its Power Stone. Failure to do this causes an infinite number of Sniperwilds, who will no longer drop their items, to begin spawning and attacking with unavoidable slingshot bullets until you escape the area.
Fat Bandits, if you're a lower level, and especially in the Coliseum tournaments. The Stop spells help, but only so much.
Black Fungi, hostile versions of the White Mushroom, emit poisonous clouds which continuously drain your health, and they can turn to stone and make themselves invincible for a period of time. Fortunately, if you defeat them, they give out a large sum of EXP, making them useful for leveling up when you first visit Agrabah (though they are a rare encounter).
Good Bad Bugs: If you use a Summon just after doing a combo finisher while the EXP Zero ability is on, the damage of the finisher will be dealt for every hit done by the Summon. This can be used to quickly shred through some late-game bosses, which helps immensely in Speedruns.
Ansem: Look at this tiny place. To the heart seeking freedom, this island is a prison, surrounded by water. And so, this boy sought to escape his prison, and he opened his heart to darkness.
As noted on the Dramatic Irony page, Ansem's manipulation of Riku becomes even worse when you remember that Terra—the man tragically fated to become Xehanort (and this game's "Ansem" by extension)—not only made Riku his successor, but promises to someday show him the worlds that exist outside of the Destiny Islands.
In Atlantica, King Triton exiles Sora because he claims that "the key bearer shatters peace and brings ruin". He must've heard about the Keyblade War.
Anyone who's seen James and the Giant Peach would recall the undead pirate scene with Jack Skellington and Donald Duck. Well, they can both fight alongside each other in this game while in Halloween Town (though Donald is a Mummy instead). The phantom rhinoceros in the film (that killed James' parents) also resembles the Behemoth.
The bonus boss fight with the Unknown/Xemnas. The way he fights is by using two red blades, throwing out lightning, quick flashes of movement, an incredible amount of brute strength, and lots of acrobatics. Flash forward to 2013, and Darth Sidious fights the exact same way against Darth Maul and Savage Oppress in The Clone Wars. Maybe now that Disney owns Star Wars, we could see Xemnas face off with Sidious?
One group of Heartless in the Hades Cup, at the 25th seed and just before the rematch with the Opposite Armor, is called "Avengers." Years later, Disney acquired Marvel Comics and now owns The Avengers.
Maleficent tells Riku that "he's like a son to her," and tries to groom him into aiding her to conquer the universe, though Riku ultimately turns against her. A different continuity shows that Maleficent has a daughter named Mal, who also turns against her following a foiled attempt to steal the Fairy Godmother's wand.
Also, the end scene of the first visit to Olympus Coliseum is when Hades tells Maleficent to get lost. The third film reveals that Hades is Mal's father.
Sora replaces Christopher Robin in the Winnie the Pooh world, helping Pooh find all of his missing friends. Flash forward to 2018, and this is the exact plot at the start of Christopher Robin, with the titular character reclaiming his territory!
The Heartless invasion. Although this fact is pretty heavily glossed over and not really discussed much, it is stated at least once that it has completely destroyed several entire worlds by the time the game starts, presumably killing hundreds of billions of people. The few survivors in Traverse Town are, for all intents and purposes, interdimensional refugees, condemned to spend the rest of their existence well and truly homeless, huddling together and trying to preserve what remains of their culture and civilization. It's basically an After the End scenario on a hilariously massive scale.
Birth by Sleep Final Mix reveals that worlds consumed by darkness aren't necessarily destroyed... but are now stuck in a bleak, nightmarish dimension. A Fate Worse than Death, perhaps?
All of the lost worlds are restored via a Reset Button, pushed by none other than Sora; additionally, the Summon Gems are stated to contain spirits that survived the destruction of their world. Two of them appear in Kingdom Hearts II.
Moral Event Horizon: Clayton, after being caught trying to shoot Terk, swore genocide against the gorillas, causing the Heartless to come. By the climax of Deep Jungle's arc, he's succumbed to The Power of Hate, and Tarzan claims "Not Clayton. *&&X% (heart). Not Clayton," signing Clayton's death warrant.
Jafar uses his first wish from Genie to reveal the Keyhole for Agrabah, which puts it at risk of the Heartless destroying it. While Riku had no idea that his actions resulted in the death of his world, Jafar outright knows that his wish amounts to genocide, and does an evil laugh right afterwards.
The absolutely hilarious sound effects that play when Clayton is smacked.
"Do de do de do!" when you solve a puzzle.
The satisfying "clunk" from when you lock a world's Keyhole.
Some of the Heartless make cute noises when you hit them. Bouncywilds actually make the same noise as Cactuars.
The Disney voices, both the returning and the spot-on impressions.
Beast saying "Step aside," while doing his charge attack. You'll love the signal when he practically one shots a bunch of Heartless.
Narm: There are a few instances where a character's lips are moving with their dialogue just fine while their teeth and/or tongue are visibly flipping out within the confines of their mouth.
One-Scene Wonder: Mickey's appearance at the very end of the story. Throughout the game, it's obvious that he's the king that everyone's referring to and his presence seems to be just out of reach. But when he appears, not only does he one-shot several of the most powerful kind of Heartless you can encounter in the game, but he also has a major role in saving the day!
Okay, who else got ambushed by Heartless at the Rabbit Hole in Wonderland? You may suspect it when you notice that the save point is the same temporary version in the Rose Garden where you fight the Queen of Hearts...
But the Heartless attack on Destiny Islands is just cruel (at least in the PS2 version). If you dillydally too long in the beachside shack? THE SAVE POINT DISAPPEARS AND THE HEARTLESS ATTACK!!
In general, the constant attacks by Heartless acclimate you to battle, to the point that when you enter a non-save point area and there aren't any Heartless attacking you, it's a real cause for alarm. In Final Mix, this eerie calm usually heralds the arrival of a new, rare type of Heartless.
Porting Disaster: The PS4 port included in HD 1.5 + 2.5 ReMIX was originally this upon release, mainly due to its 60fps framerate causing noticeable issues with certain aspects of the gameplay (physics, scripted events, etc.) that were hard-coded to the original PS2 version's 30fps framerate. The most noticeable side effect of this was certain boss battles (Sephiroth, most notably) becoming significantly harder than they should be. Thankfully, the vast majority of these problems were fixed after various patches, making it now lean much much more toward being a Polished Port.
The Gummi Ship segments are often cited as long, slow, too frequent, and unengaging.
Synthesis in Kingdom Hearts was slightly time consuming but the rewards always made up for it. Final Mix has more items that are just as worth it (Crystal Crown), but with the addition of new enemies, have made synthesis twice the pain in the ass. Special mention goes out to finding Power Stones and Serenity Powers.
The unskippable cutscenes. This is particularly unbearable for the battle against Ansem-Riku. The cutscene before the fight clocks in at a whopping two-and-a-half minutes. That means every time you die, you have to wait through that entire two-and-a-half minute cutscene before you can try again. Thankfully, the cutscenes were made skippable in the re-releases that followed.
For some, it was the fight with Clayton that was this.
Riku extending his hand to Sora in the intro, and then Sora looking up while in the Awakening at the end of the intro.
Sora and Kairi sharing a moment on the dock right before the storm hits.
Sora meeting Donald and Goofy.
The first time Sora flies in Neverland, and then whenever you visit Big Ben. It's a truly beautiful location, helped by the fact you get to fly freely around it.
"I don't need a weapon, my friends are my power!"
For those who had difficulty with some bosses, the proceeding cutscene before some bosses was this:
"NOT CLAYTON! Hee hoo hoo hoo ha! NOT CLAYTON!"
"There's NO WAY you're taking Kairi's heart!"
"I know now, without a doubt, Kingdom Hearts...is light!" The door opening and light shining on Ansem is considered so iconic it was used in opening movies in later games.
Special Effect Failure: A few spots in the 1.5 ReMIX version, particularly in Gummi Ship paths, show that the game wasn't developed with widescreen in mind and can spawn or cull objects a bit too close to the edges of the screen. The issue is less noticeable in the main game, although a few instances still crop up, such as in the Phantom bonus boss's introductory cutscene.
That One Achievement: The Gummi Ship Collector trophy in the 1.5 version, which involves getting every Gummi Ship blueprint in the game. For the majority of obtaining the blueprints, this means fulfilling some truly insane mission requirements traveling between worlds with the Gummi Ship, like doing Atlantica's third mission (do not collect items, and get a high score of 260 points or more; it's a Luck-Based Mission if Monstro is first encountered on this route), in a minigame widely considered a Scrappy Mechanic prior to its revamp in Kingdom Hearts II. The 1.5 + 2.5 PS4 version made it a bit easier by making it so you "only" need 30 blueprints instead of all of them, but it's still a pain.
That One Attack: SUBMIT!. This is the sound of Ansem's Guardian possessing and then preventing you from doing anything properly during the final boss, all while Ansem yells at you to Open your Heart! and receive a barrier attack to the face.
Atlantica. The world has extremely awkward swimming controls that complicate movement and combat, navigation can be confusing due to the layout, and there are two difficult boss fights against Ursula.
Monstro is a prime example of terrible level design, mostly being a confusing maze of passageways that look nearly exactly the same.
Deep Jungle, mostly due to the constant backtracking you have to do to advance the plot.
They Wasted a Perfectly Good Character: Jasmine proved herself to be a capable Action Girl in the Aladdin TV series, and was pretty proactive in the first film too. Here she's turned into a Damsel in Distress just to prop up the Disney Villains (Jafar captures her easily and we hear her cries for help throughout the Pot Centipede boss battle, and then in the Cave of Wonders while Sora and the others are facing Genie Jafar, Riku captures her off screen.)
Chernabog popping up as a boss in the End of the World was pretty unexpected, especially since he has no connection to another of the other worlds or characters (except to Mickey in a roundabout way, through their shared appearance in Fantasia, which was once considered as a world; the brooms from that movie also appear).
Beast's appearance as a party member in Hollow Bastion is meant as a surprise, since Hollow Bastion is a series-original world hyped up as Maleficent's stronghold and it has nothing to do with Beauty and the Beast. Beast's actual world only first appears in II.
Unintentionally Unsympathetic: Donald Duck comes off in this game as a complete Jerkass for mental child abuse towards Sora. He tells the boy to join them and lies that he'll help find his friends. Then the trio arrive at Deep Jungle, and Donald shows off his true colors by telling Sora and Goofy that they are not landing (and let the Heartless consume it), even as Sora pleads to let them land so that he could check for his friends. After landing, Sora is separated from them; Goofy shows concern, but Donald huffs that they don't need Sora, the only person who can save the universe! Later, Donald coldly denies Riku a spot in their party. He does not give any reason; he just says "forget it," indirectly causing Riku's Start of Darkness. Yes, Donald does get his priorities straight as the game advances on, but the events of Deep Jungle and the reunion with Riku are major Kick the Dog moments from him reminiscent of Ratchet's treatment towards Clank in the first game of their franchise.
The Woobie: Kairi, who lost her home, family and friends twice(first with Hollow Bastion, and then with Destiny Islands). And then there's the ending of the game. Just watch it and try not to feel for the girl.
They Changed It, Now It Sucks!: Some people hated that Kingdom Hearts 1.5 HD Remix replaced all the original music with new, live-orchestrated versions.
WTH, Casting Agency?: Casting Lance Bass as Sephiroth raised more than a few eyebrows from the Final Fantasy part of the fandom. It's especially jarring since you only hear Sephiroth speak through battle grunts and his voice is so echo-y that you could barely understand him. It begs the question why they even bothered getting a Celebrity Voice Actor.
Woolseyism: In the Japanese version, the Chernabog battle has the same music as any other Disney villain battle. In English? Whatelse?
Complete Monster: This incarnation of Ansem, Seeker of Darkness, the Heartless form of Xehanort, is even more malicious than the original. Masterminding the Heartless' invasion of several worlds and Maleficent's plan to capture the Seven Princesses of Heart in order to open the Final Keyhole, Ansem Mind Rapes Riku so that he can possess his body. He stabs Maleficent with a Keyblade in order to destroy her once she's no longer of use to him, and then deceives Sora into using that same Keyblade to make what would ultimately be a Senseless Sacrifice, turning Sora into a Heartless and unsealing the Final Keyhole. When Riku's heart fights back from within to stop him from attempting to kill Kairi, Ansem uses his power to banish Riku's heart into the Dark Realm. Ultimately planning to open the Door of Darkness to let darkness consume all existence, Ansem shows nothing but glee towards his destructive ambitions. Returning after defeat as a specter within Riku's heart, Ansem attempts to play the boy's own emotions against him in order to take control of the boy's body once more, vicious to the end. Showcasing no redeeming features and played dead seriously against the manga's usually lighthearted and silly tone, Xehanort's Heartless would do whatever it took to gain ultimate knowledge and power, and to sate his undying hunger for darkness.